OCR Biology F211 Exam - Tues 11'th January 2011

ummm they are about 30 pages and they have pictures/diagrams that I did on Paint as well!
I will attempt to put them up tomorrow okay? I have to go babysitting now, joy

Can you email me the notes please?

Hey can anyone give me the link for the mark scheme for Tuesday 8TH JUNE 2008 TRANSPORT LEGACY paper? I would really appreciate it. Thanks

Help i dont understand how water moves up the xylem.
Quote me if you reply thanks.

go on paper bank
have anti-virus software though

i bet theres going to be a 5 marker on setting up a potometer.

i bet theres going to be a 5 marker on setting up a potometer.

lmao i hope not!
i was doing the specimen paper and literally, they gave 2 whole pages and 7 marks on a question asking how to set up a potometer :| i was just like, are you kidding me? i wrote like 5 lines and still managed to get 5 marks lol dunno why they gave 1 and half pages for the other 2 marks :|

Lol can you please explain how to set up a potometer and any other necessary information? please?!

hey can anyone explain fetal haemoglobin 2 me plz???
still dont understand it

I was very confused with this last year (i'm resiting F211 this January). Sods law it came up in june 2010 with this question: "Explain why the curve for fetal oxyhaemoglobin is to the left of the curve for adult oxyhaemoglobin"

So good news for this January is it's VERY unlikely to come up in the paper. So i wouldn't worry too much about it

Anyone have any predictions for the exam on TUESDAY (eeek)?
I'm thinking full details of mitosis, heart valves (atrioventicular/semi lumar), mechanism of transport in phloem, transpiration...

i'm hoping nothing on homologous chromosomes, budding, Bohr shift and fetal haemoglobin...but these came up in June 2010 so tis unlikely

i bet theres going to be a 5 marker on setting up a potometer.

Lol well this was in the mark scheme

1 cut (healthy) shoot under water (to stop air entering xylem vessels);
2 cut shoot at a slant (to increase surface area);
3 check apparatus is full of water / is air bubble free / no air locks;
4 insert shoot into apparatus under water / AW;
5 remove potometer from water and ensure , airtight / watertight, joints around shoot;
6 dry leaves / AW;
7 keep , condition(s) / named condition(s) , constant;
8 allow time for shoot to acclimatise / AW;
9 shut screw clip;
10 keep ruler fixed and record position of air bubble on scale;
R ‘move bubble to end’ ideas
11 start timing and, measure / calculate, distance moved per unit time
/ AW;

hope that helped.

i probably won't remember that though lol :P

but seriously, what good will it do us knowing how to set up a potometer?? like, i don't really see how knowing that will be beneficial to my future

haha you just answered the question!

Hey.. water moves up the xylem in 3 ways

1) Root pressure/Hydrostatic pressure:
As the minerals are ACTIVELY transported into the xylem vessel, this lowers the water potential of the xylem vessel causing water from the endodermis cells to move down the water potential gradient and enter the xylem by osmosis. This increases the root pressure/hydrostatic pressure. At the top of the plant, water is lost by transpiration so the hydrostatic pressure at the top is low. Water then moves down its hydrostatic pressure gradient UP the xylem vessel.

2) Transpiration pull/stream
Water is lost from the aerial parts of the plants by transpiration. This loss of water must be replaced by water coming up the xylem. Water molecules are attracted to each other by cohesion. The cohesive forces are strong enough to hold the molecules in a long chain/column. As water is lost from the top in a chain, this puts tension in the xylem vessel. This ensures that water moves up the xylem as a long chain/column

3) Capillary action
Water molecules are also attracted to the walls of the xylem vessel. This is called Adhesion. The adhesive forces are strong between the water and xylem 'cos the xylem is narrow. This attraction also allows water to flow up the xylem vessel

Thats all Hope that helped. Its good revision for me too x